Models have been developed for curing leukemia in mice with chemotherapy plus lymphocytes from donors immune to the leukemia. This approach has been limited by the requirement that the donor be exposed to tumor material and the need for large numbers of immune lymphocytes. It is now possible to render lymphocytes immune in vitro and to grow them in large numbers with the air of growth factors (interleukin 2) present in the supernatants of mitogen or antigen stimulated lymphocytes. The experiments outlined in the current proposal will utilize techniques for T lymphocytes subset identification and selection, for growing cells with Interleukin 2 and for cloning proliferating cells, in order to identify and characterize the different types of lymphocytes grown and to determine how they might be best used in the therapy of advanced disseminated murine leukemia.